Energetics of sodium dodecylsulfate-dodecyldimethylamine oxide mixed micelle formation

Thermodynamic parameters and counterion binding to the micelle in binary anionic surfactant systems

“…The regular solution interaction parameter is normally assumed to be constant over the entire range of composition [26] but may have a dependence on temperature [30]. In some instances, the interaction parameter has been found to be dependent on micellar composition [26,[30][31][32][33]. The best fit for the interaction parameters in the current study are 0.00 ± 0.10 and À1.05 ± 0.20 for the NaDS/ NaOBS and NaDS/NaDeS systems respectively.…”

Thoughts on the ideal behavior of mixed micelles and the appropriate application of regular solution theory (RST)

“…Thus, as for the solvent mixtures, the knowledge of the enthalpy of mixture is essential for the comprehension of the systems [29][30][31].…”

Are the mixtures of homologous surfactants ideal?

“…This energy (and then the β M value) is expected to depend much on the surface charge density of micelles and the ionic strength, and less on the size and shape of micelles [37,38]. The μ excess mix value does not take into account the change in the degree of association of the counterion upon surfactant mixing [19][20][21].…”

“…Theoretically, β M is independent on both temperature and the composition of the micelle. However, in practice β M is temperature dependent [19][20][21][22] and it often depends on the micelle composition [22,23], so that an average value is commonly used. In spite of these limitations, the β M parameter quantitatively captures the extent of nonideality in a single number that can be easily compared among different pairs of surfactants.…”